Photographic lens



W. MERTE PHOTOGRAPHIC LENS Filed Oct. 12. 1929 dn' 58 Z -12 dz 6 Y Jn van/0n; w M

Patented Oct. 6, 1931 1,826,362

" UNITED STATES PATENT OFFICE WILLY name, or JENA, GERMANY, ASSIGNOR r THE rmm cam. znrss, or JENA, GERMANY rno'roonnrmc LENS Application filed October 12, 1929, Serial No. 399,344, and in Germany October 23, 1928.

This invention relates to photographic and diam lenses, i. e; spherically, comatically, chromat- 1525 =12 ically and astigmatically corrected lenses 47 1 1 9 that consist of three parts, viz. of a diverg- Kinds f glass ing bi-concave part and of two converging 0 parts that enclose the former, of which lat- I II III IV ter the one next to the incident light is comm==1.62177 1.52547 1.62559 1.62177 posed of two members cemented together and 1 56.5 52.8 35.7 56.8 the other one is a non-cemented single part. I claim 10 The e lenses are especially for Short 1. A photo raphic lens consistin of a di- Stantaneous Photographs d tlvlereflore verging bl-COI lCflVe part and of two convergmust have. a great aperture F ing parts that enclose the former, of which zq to i ag a l f lgg' latter the one next to the incident light is so ls-amp .3 Y y n i composed of two members cemented together p e .enses W en 6 mm en i that the cement-ed surface is converging and Penal of rays 15 compqmtwe y Tong y the other of the two conver in parts is a non- Stmngulated before stnkm-I dwemmg cemented sin le part the zert ex distance betas;ain:assassinated {rant ewe e tion aims at providing the diverging lens at the incident light and the front surface of the 65 I possible to keep the errors of the oblique penoffers the same advantages.

$5 With, this lens the astigmatism is corrected diver in part'bein greater than one tenth a comparatively great distance from the two e e s bounding surfaces of the part that is next to of the total focal lehflth of the P L P lens. and the clear distance between the back the mcident llght. Then. with forms of lens vertex o the p next to the incident light and the front vertex of the dispersive part being greater than one twentieth of the focal the lens, when applied for magnification of length of the photogmPhlc lensphotographs. i. e. whe n it is used in a sense ig ggffi zgfigg gsggfgglfiisg opposlte to'that Obtmnmg m photograph the refractive index of the dispersive member The. drawing and the table below give as f h to theohlcideht h the }6- an example alongitudinal section through a fractlve mdlvces refen'mg to the 141119 helhg photographic lens corresponding to the inan greater than 7 I 1:27v 3 In a photographic lens according to mtlon whose aperture who Is claim 1 the dIfi'er ence between the refractive go indices on the cemented surface of the part next tothe incident light being greater than seven hundredths.

that correspond to the invention. it is also oils within narrow limits. It is obvious that for an image angle of 45. The figures refer to a focal length of the photographic lens of umts- 4. In a photographic lens according to 40 man T u-m and distances claim 1 the absolute value of the radius of a5 4- 41,6 d 8.8 curvature of the cemented surface of the part r 66.1 d 2.8 next to the incident light lving between the r,= 378-.0 12 2.5 absolute values of the radii of curvature of 533 1 5,6 the two adjacent surfaces. 5 3&0 5,3 WILLY MERTE. 0o 

